Abstract:During the anaerobic digestion of biomass,large amounts of organic acids were produced.This results in an inhibitory effect on anaerobic microbiology,which in turn inhibits large-scale production of hydrogen.In this study,butyric acid was use as stress on the sludge,and it was found that the production rates of butyric acid,acetic acid and hydrogenwas reached at 400 mmol/mol,1100 mmol/mol,3690 mL/mol,respectively,which was higher 110%,54% and 65% than that of the corresponding values in the control group.Moreover,glutamate acid decarboxylase(GAD) activity,dehydrogenase activity and the content of DNA was increased to 11.6 μm/(g·TS·h),6982.12 μg TF/(g·TS·h) 14.72 ng/mL,with an increment of 48%,50%,10.7%,respectively.and the content of extracellular polymeric substances(EPS) have improved significantly,loose bound protein,loose bound polysaccharide,tight bound protein and tight bound polysaccharide content were 147%,34.8%,35%,21.6% higher than that of the control.The results demonstrate that the appropriate concentration of butyric acid stress on sludge can excite acid tolerance response(Acid tolerance response,ATR) and to improve acid tolerance of sludge,and improve the efficiency of anaerobic hydrogen production.
